1. Field of the Invention
The invention relates to polymeric, including oligomeric, compositions containing a poly(alkylene carbonate) backbone.
2. Background of the Invention
Poly(alkylene carbonate) polyahls are ranndomized polymers containing alkylene carbonate moieties and ether moieties such as di- and higher polyalkylenoxy units. An alkylene carbonate moiety is a repeating unit comprising an alkylene group bound to a carbonate moiety. Some of the known poly(alkylene carbonate) polyahls are non-ionic surfactants.
In 1978, DE 2,712,162 to Stuehler disclosed non-ionic surfactants containing carbonate in the backbone. A variety of surfactants have been prepared by Langdon and described in a series of patents. U.S. Pat. No. 4,072,704 described the coupling of polyethylene glycols and polypropylene glycols with either dialkyl carbonates or formaldehyde to give materials with surface active properties. In U.S. Pat. No. 4,353,834, it was described how long chain amides or sulfonamides have been coupled with hydrophilic polyglycols using dialkyl carbonates or esters of dicarboxylic acids to give materials with surface active properties. This work was extended in U.S. Pat. No. 4,504,418 to include polyoxyalkylene polymers and monofunctional aliphatic, aromatic or aliphatic-aromatic alcohols coupled by alkyl carbonates or esters of dicarboxylic acids to give materials with surface active properties.
U.S. Pat. No. 4,330,481 to Timberlake et al. described the preparation of surfactants by reacting alcohols or alcohol ethoxylates with ethylene carbonate. These products were then further reacted with ethylene oxide to produce different surface active materials as reported in U.S. Pat. No. 4,415,502. The preparation of surfactants and functional fluids by reacting alcohols, phenols or carboxylic acids (or their alkoxylated derivatives) with alkylene carbonates or alkylene oxides and carbon dioxide was described in U.S. Pat. No. 4,488,982 to Cuscurida.
U.S. Pat. No. 4,382,014 to Sakai et al. described the preparation of surface active materials by reacting alcohols, carboxylic acids or primary or secondary amines containing four or more carbon atoms or substituted phenols with alkylene carbonates in the presence of an -ate complex of a metal or Group II, III or IV of the Periodic Table having at least two alkoxyl groups.
Low molecular weight polyoxyethylene glycol monomethyl ethers have been coupled using phosgene or alkyl carbonates to give materials useful in formulating brake fluids and as synthetic lubricants, as disclosed in U.S. Pat. No. 3,632,828. The coupling of monofunctional alcohols, phenolics or their ethoxylated derivatives using diphenyl carbonate to give surfactants was disclosed in U.S. Pat. No. 3,332,980.
U.S. Pat. No. 4,267,120 to Cuscurida and Speranza describes novel polyester polycarbonates obtained by reacting a cyclic organic acid anhydride, a 1,2-epoxide carbon dioxide and a polyhydric compound in the presence of a basic catalyst. The resulting polyester polycarbonates are terminated with hydroxyl groups and are not acid-functional materials or surfactants.
These non-ionic surfactants contain a carbonate backbone which can be degraded by bases, strong acids or under biodegradative conditions. This makes these surfactants fugitive and biocompatible since they do not persist in the environment. Unfortunately, these non-ionic poly(alkylene carbonate) polyahl surfactants have limited applications due to their very poor water solubility and wetting times.
In addition, these non-ionic surfactants also form poor foams evidencing poor foam stability, which in specific instances may be an advantage or a disadvantage depending on the particular application. Also, fairly high concentrations of these non-ionic surfactants are required before any surface active properties, like lowering the surface tension of water, are evidenced.
In view of these shortcomings of poly(alkylene carbonate) polyahl surfactants, there still is a need for biodegradable surfactants having the ability to disperse in water and/or solubilize incompatible components.